Short answers, pulled from the story.
Glucose is the most abundant monosaccharide, a simple sugar in the carbohydrate family. It contains six carbon atoms and an aldehyde group, making it an aldohexose, and it is often abbreviated as Glc.
Glucose was first isolated from raisins in 1747 by the German chemist Andreas Marggraf, and discovered in grapes by Johann Tobias Lowitz in 1792. The name comes from the Ancient Greek gleukos, meaning wine or must, which derives from glykys, meaning sweet.
Glucose is the body's key source of energy, providing about 3.75 kilocalories per gram through respiration. Anaerobic respiration nets two ATP molecules per glucose, while aerobic respiration yields a maximum of 30 or 32 ATP molecules depending on the organism.
Diabetes is a metabolic disorder where the body cannot regulate blood glucose, either from a lack of insulin or from cells failing to respond to it. Many long-term complications, including blindness, kidney failure, and peripheral neuropathy, are probably caused by the glycation of proteins or lipids.
Glucose and dextrose refer to the same molecule, specifically D-glucose. The term dextrose is typically used in clinical and nutritional settings such as food labels, while glucose is used in biological and physiological contexts.
Glucose is produced industrially from starch by enzymatic hydrolysis, yielding glucose syrup with more than 90% glucose in the dry matter and an annual worldwide volume of 20 million tonnes. The United States uses corn starch almost exclusively, Europe uses potato and wheat starch, and tropical areas use tapioca starch.
Glucose has a lower tendency than other aldohexoses to react with the amine groups of proteins, a damaging reaction called glycation. Its stable cyclic form, with hydroxy groups in the equatorial position, means it spends less time in its reactive open-chain state.